1. Field of the Invention
The present invention relates to a sprocket mounting carrier for a bicycle.
2. Description
This invention relates to a sprocket mounting carrier for a bicycle for carrying a first sprocket having a central hole of which the bounding wall has at least four first cams whose tops are the first cams innermost curved surfaces having a first top diameter. The sprocket mounting carrier has a cylindrical body having an outside with an outside diameter and at least four first grooves in the outside of the cylindrical body, the at least four first grooves having bottoms, which are the innermost curved surfaces of the first grooves, wherein the bottoms have a first bottom diameter whereby the first cams engage with the first grooves and/or the bounding wall engages with the outside, so that the first sprocket both in the radial direction and in at least one tangential direction cannot move relative to the sprocket mounting carrier. Furthermore, the sprocket mounting carrier has second sprockets that have a further central hole having a bounding wall with at least six second cams projecting radially inward, where the tops of the second cams are the innermost curved surface of the second cams, and have a second top diameter. The outside of the cylindrical body has at least five second grooves having bottoms, which are the innermost curved surfaces of the second grooves. The bottoms have a second bottom diameter, wherein the first bottom diameter is smaller than the second bottom diameter. The second grooves engage with the second cams, and/or the bounding wall of the further central hole engages with the outside so that the second sprocket both in the radial direction and in at least one tangential direction cannot move or can hardly move relative to the sprocket mounting carrier.
Engagement in this respect is to be understood to mean that at least a plurality of the cams are in contact with the bounding walls of the grooves. After being mounted, the tops and the side walls of the cams are in contact with or have a close fit gap to the grooves due to manufacturing tolerances. During operation this clearance will often be neutralized because the sprockets will transfer the torque produced via the chain to the sprocket mounting carrier. The side walls of the cams then come into contact with the side walls of the grooves. During the mounting of the sprocket on the sprocket mounting carrier usually one or two of the cams will hit with their tops against the bottoms of the grooves, for example as a result of gravity. The other cams are then positioned at a slight distance from the bottoms of the cams. As a result, the cams are captured by the grooves of the sprocket mounting carrier and thus rotate together.